Del Rio's dismissal came with the possibility of landing Gruden firmly in mind, according to the person with knowledge of the situation, who spoke on the condition of anonymity because no deal with Gruden has been struck. According to that person, the negotiations could be complicated but the Raiders believe that Gruden is ready to return to coaching and that he is eager to do so with the team that he formerly coached.

ESPN, for which Gruden works as the analyst on its "Monday Night Football" broadcasts, reported Saturday that Raiders owner Mark Davis is prepared to make a lucrative offer to Gruden that could include an ownership stake in the franchise. If ownership of the Raiders is involved in Gruden's deal, the arrangement would have to be vetted and ratified by other NFL owners. It would require the approval of at least 24 of 32 owners league-wide.

Gruden coached the Raiders between 1998 and 2001 before being sent to the Tampa Bay Buccaneers in a rare trade of an NFL coach. That swap was orchestrated by late Raiders owner Al Davis, Mark Davis' father. Gruden won a Super Bowl title in his first season with the Buccaneers, beating the Raiders, and lasted in Tampa through the 2008 season. He has not coached since, although there has been nearly annual speculation about his prospective return. He turns 55 in August.

The Raiders can offer not only an overwhelming financial deal and the chance for Gruden to return to the franchise, but also the opportunity for him to coach a contending team with a productive quarterback, Derek Carr, that is about to make a move to Las Vegas.

ESPN announced Monday that Gruden remains scheduled to be in its broadcast booth for its telecast of this weekend's Titans-Chiefs AFC playoff game in Kansas City.

Gruden reportedly has begun lining up a prospective coaching staff. Some within the league believe it's possible that his defensive coordinator will be Paul Guenther, the widely respected defensive coordinator of the Cincinnati Bengals. But Guenther also could be a head coaching candidate in Cincinnati if Marvin Lewis does not remain in the Bengals job.

Mark Davis and the Raiders will have to deal with the fact that Gruden has considered other jobs in previous years without actually taking one of them. He was linked in recent weeks to a possible return to Tampa. But the Buccaneers told their current coach, Dirk Koetter, that they will retain him, prompting speculation that Gruden chose the Raiders over the Buccaneers.

Another complicating factor for the Raiders is the Rooney Rule, which requires each NFL team with a head coaching vacancy to interview at least one minority candidate. The Raiders must comply with the rule, even amid the widespread belief that they already have settled on Gruden as their coach, or face disciplinary measures by the league.

In 2003, former NFL commissioner Paul Tagliabue fined Matt Millen, then the president of the Detroit Lions, $200,000 for failing to interview a minority candidate before hiring Steve Mariucci as the team's coach. Tagliabue told NFL owners during a meeting that year that any future violation of the rule could result in a fine of $500,000 or more for conduct detrimental to the league.

Millen said when he hired Mariucci that he'd attempted to interview minority candidates but they had declined to interview for the job because they believed it was certain that Mariucci would be hired.

Tagliabue wrote to Millen when assessing the fine: "While certain of the difficulties that you encountered in seeking to schedule interviews with minority candidates were beyond your control, you did not take sufficient steps to satisfy the commitment that you had made."

Neither the Lions' nor the Bears' move was surprising. There had been plenty of speculation about the job security of both Fox and Caldwell. But the levels of justification associated with the two moves were far different.

In the Bears' case, there was little choice but to move on from Fox. It simply wasn't working. The Bears just finished a 5-11 season and were 14-34 in three seasons under Fox. It was clear that they needed to turn over the development of prized young quarterback Mitchell Trubisky to someone else.

The Lions' choice was far less clear-cut. They just finished a 9-7 season. Caldwell was 36-28 in four seasons in Detroit and took the Lions to the playoffs twice. They'd been to the postseason once in 14 years when he arrived. Caldwell is the Lions' winningest coach of the Super Bowl era.

Arians, 65, became one of the rare coaches to leave on his own terms, stepping aside after five mostly successful seasons in Arizona.

"It's been a great ride," Arians told reporters at his retirement announcement. "I told you before there would be reasons. Family is a big one. I will miss the game. I'll actually miss you guys. Hell, I might be on your side. I don't know."

The decision did not come as a surprise. There had been speculation that Arians would walk away. But he said he did not make his decision until Sunday when the Cardinals won at Seattle, 26-24, on a late field goal made by Arizona's kicker, Phil Dawson, and a final-minute miss by the Seahawks' Blair Walsh. Arians said he told his team Sunday, but the Cardinals kept things officially under wraps until Monday.

"I probably truly didn't know until that kick went through that I was going to retire," Arians said. "I know everybody speculated and everybody speculated for months and everybody had a story. You now have the story."

The Cardinals went 8-8 this season and were 15-16-1 over the past two seasons after three straight seasons with 10 or more victories. They made the playoffs in Arians's second season and reached the NFC title game in his third season.

Arians was emotional as he spoke Monday. But he said his tears were tears of joy and peace.

"I'll miss the players," he said. "I'll miss coming out of the locker room, hearing the national anthem. That still gets me. Somehow, some way, I'm going to be in touch with the game."